Machine for forming double lap flaring on tubing



Dec. 2, 1952 E. 4. DE voss 2,620,013

MACHINE FOR FORMING DOUBLE LAP FLARING ON TUBING Filed Feb. 26, 1949 3 Sheets-Sheet 1 w Q Ex 9% v k3 Q Hum Au, V I I I NI. I G a a R: :R I r M s h 1 3 I. u PI i w I III III N l I A m m... ME #11 In. 2 E :1 :3 Eli ZEN/ v 0: Vans 2,620,013 MACHINE FOR FORMING DOUBLE. LAP FLARING ON TUBING Filed Feb. 26, 1949 E. A. DE voss s Sheets-Shet 2 Dec. 2, I952 ITZV'EZ? Tar [aw/Iv 14. 05%:

E. A. DE voss 2,620,013

MACHINE FOR FORMING DOUBLE LAP FLARING ON TUBING Dec. 2, 1952 3 Sheets-Sheet 3 Filed Feb. 26. 1949 Patented Dec. 2, 1952 MACHINE FOR FORMING DOUBLE LAP FLARIN G ON TUBING Edwin A. de Voss, Los Angeles, Calif.

Application February 26, 1949, Serial No. 78,616

6 Claims. 153-805) This invention relates to a machine for forming a double lapped flared end on tubing.

Specifically, the invention relates to a machine for supporting the inside of a hollow article such as a tube against collapse in a die while punches successively act on the member to first bow it against the die, and to then fold the end portion of the member into the bowed portion for forming a double walled flared end on the member.

The machine of this invention is especially useful in forming double lapped flared ends on metal tubing of the type used in automotive, airplane, mechanical refrigerator, and the like conduits wherein a fitting such as a union, elbow, nipple, or tee has a tapered end inserted in the flared end of the tube and wherein a compression nut bottomed on the flared end of the tube has a tapered shoulder coacting with the tapered end of the fitting to sealingly clamp the double lapped portion therebetween.

The machine of this invention includes dies for securely gripping the outer circumference of the tube to be flared, together with tapered die faces for shaping the conical outer face to be formed on the end of the tube. A compound punch assembly coacts with the dies and includes telescoped mandrel, finish or cone punch, and upset punch parts. Suitable mechanism actuates these parts in proper sequence to close the dies around a mandrel supported portion of a tube, advance the upset punch while guided by the mandrel to bow the end of the tube against the tapered die face, open the upset punch, advance the finish or cone punch into the bowed portion to form the double lap, and to then open the dies and withdraw the mandrel from the finished tube end. These successive operations can be conveniently controlled by cam mechanisms and a preferred embodiment of such mechanisms includes a fluid pressure-actuated cam carrier. A suitable die control includes fluid pressure actuated dies and an electrically operated fluid valve controlled from a switch that is automatically shifted under the influence of the cam mechanism.

An important feature of the invention resides in'the provision of the mandrel to support the tube against collapse and to guide and align the punches.

Another feature of the invention is the provision of a cone or finish punch which rides on the-mandrel and, when being moved toward operative position, automatically opens up the upset punch.

It is, then-an object of this invention to provide a machine for quickly and uniformly forming double lapped flared ends on tubes.

A further object of the invention is to provide a mandrel for aligning a tube in a die and mechanism for pulling the mandrel out of the tube.

A still further object of the invention is to provide a machine for forming double-walled flared ends on tubes while supporting the tube against collapse.

A further object of the invention is to provide a multiple punch assembly composed of tele- Another specific object of the invention is to provide a compound punch for a double lap tube flaring machine with a finish punch and. a split upset punch so arranged that the upset punch is automatically opened as the finish punch comes into operating position.

A further specific object of the invention is to provide a machine for forming double-walled flared ends on tubing wherein fluid pressure means and cams automatically control sequential operation of the machine parts for minimizing manual adjustments and operations.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of a preferred example only, illustrate one embodiment of the invention and one variation from a portion of this embodiment.

On the drawings:

Figure l is a side elevational view, with parts broken away to show underlying parts and with portions in vertical cross section, of a double lap tube-flaring machine according to this invention, and showing the starting position of theparts with the tube end disposed over the mandrel and the dies closed around the mandrel-supported tube end. T

Figure 2 is a horizontal cross-sectional view,

with parts in top plan, taken along the line II-II of Figure 1.

Figure 3 is a view similar to Figure 1 but illustrating the positions of the parts of the machine upon the completion of the double lapped flared end on the tube but illustrating the mandrel still in the tube.

Figure 4 is a fragmentary side elevational view, with parts in vertical cross section, illustrating a portion of the machine in the position assumed thereby upon completion of the, bowing or upsetting operation.

Figure 5 is a view similar to Figure l but illustrating the positions of the parts upon completion of the finish or cone punch operation.

Figure 6 is a view similar to Figures 4 and 5; but illustrating the positions of the parts after completion of all of the operations, showing the manner in which the mandrel is retracted from the tube while the cone punch holds the flared end of the tube against deformation under the influence of the retracting. action of the mandrel.

Figure 7 is a fragmentary transverse crosssectional view, with parts in elevation, taken along the line VIIVII of Figure 2.

Figure 8 is an enlarged fragmentary vertical cross-sectional view of the split upsetting punches showing the rounded upsetting faces of these punches.

Figure 9 is a vertical cross-sectional view, with parts in side elevation, illustrating a modified arrangement for opening the split upsetting punches as the cone punch or finish punch is moved into active position.

Figure 10 is a diagrammatic view illustrating the manner in which the dies are controlled.

As shown on the drawings:

The machine I!) of Figures 1 to 3 includes a pair of dies H, a compound punch assembly I2, a cam assembly I3 for actuating the punches of the assembly I2, a cam carrier I l, a cam-actuating fluid pressure cylinder I5, a pair of fluid pressure cylinders lfi'for actuating the dies II, and a switch I! on the cam carrier It for controlling actuation of the cylinders I6.

The dies II each have semi-cylindrical tubegripping recesses Ila and conical die faces Hb diverging from the gripping faces I la. The leading; end of a tube T is seated in the dies and is gripped by the seat Ila, adjacent its leading end to provide a portion T1 (Figure 1) projecting through and beyond the die faces III) for formingthe double lapped flared end on the tube.

The punch assembly I2 includes a carrier It in the form of a hollow cylindrical block slidably mounted in a surrounding bearing I9; As shown in Figure 2, the carrier I8 has. a longitudinal groove I811 along the top thereof and the hearing [9 has a setscrew threaded through the top thereofto extend into the groove Ida for hold-- ing the carrier IS against rotation in the bearing while accommodating longitudinal sliding action of the carrier through the bearing.

The front end of the carrier is milled to form longitudinally aligned spaced pairs of ears I8b on the top and bottom thereof. The rear end of the carrier I8 has pins 2| extending from the opposite sides thereof and rotatably supporting rollers 22.

The upset or bending punch 23 is composed of two half sections each of which is in the form of a semi-cylinder. Each section has a lug 2 312 on the rear end thereof extending between a pair of ears IBb of the carrier and pivotally attached thereto by a pin 24. Thus, as shown in Figure 1, top and bottom segments constitute the split punch 23 and each segment is pivotally. supported at its rear end on a pin 24 carried by the carrier I8. A coil spring 25 surrounds the split punch 23 and is seated in a groove 232) provided in the punch segment in spaced relation forwardly from the lugs 23a thereof for holding the segments in closed position.

The split punch 23 has a large diameter cylindrical bore 230 extending forwardly from the rear end of the punch to a tapered shoulder 23d which converges to a smaller diameter bore 23c. This smaller diameter bore extends through the forward end face of the punch and, as shown in Figure 8, the forward or active end face of the punch is dished at 231, to provide a concave end wall converging toward the bore 236. This concave end wall serves to guide the tube during the bowing or upsetting operation for better control of the bowed section as will be more fully hereinafter described. In addition, this concave end face 23f coacts with the tube end inwardly of the pivot pins 2% to hold the, dies closed during the upsetting operation, as shown in Figure 4'.

A cone punch 28 in the form of a hollow'rod isslidably mounted, in the bore of the carrier I18 and in the bore 230 of the split punch 23. This finish punch 26, as best shown in Figure 2,,h as a longitudinal groove. 26a along the topthereof and a set screw 2? in the groove Hint of, the, carrier I'B projects into, this groove 26a tohold the cone punch against rotation in the carrier. The forward end of the cone punch has a tapered face 2'61) forming the active end. of the punch to fold the end portion of the bowed tube for forming the double lap or double wall arrangement as will be hereinafter more fully described. The.

rear end of the cone punch projects. beyond the carrier I8 and has pins 21' extending laterally therefrom for rotatably supporting rollers 28.

A mandrel, in the form of a solid cylindrical rod 29, is slidable through the hollow cylindrical cone punch 26 and is longer than they punch to project beyond both ends thereof. The top of the mandrel 29 has a longitudinal groove, 29a therein adapted to receive a set screw 30 threaded through the groove 26a of the cone punch 26 to prevent rotation of the mandrel in the cone punch. The forward endof the mandrel is preferably slightly beveled as to 292) to facilitate insertion of the mandrel into the tube. end of the mandrel has pins 3| projecting laterally therefrom and carrying rollers 32.

The cam assembly I3 includes outer side plates 33, 33 each with a vertical slot 33a near the rear end thereof and a vertical slot 33b near the front; The vertical slot 331), however, has

end thereof. an intermediate forwardly offset portion 330 between an upper vertical portion;33d that is rear wardly displaced relative to the main elongated; bottom portion 33c of the slot beneath the offset portion 330.

The carrier I l has side plates 34, 34 straddling the rear ends of the'plates 33 and having pins 35 projecting inwardly therefrom to, rotatably support rollers 36 riding in theslots 3311., The

interposed between the plates 31, 31 and all three;

sets of plates are held together on opposite sides The rear of the mandrel 29 by transverse connecting bolts or screws 39 shown in Figure 1. The plates 38 project rearwardly from the plates 33 and 31 but terminate adjacent the slots 31a of the plates 31. These inner plates 38 have slots 38a with vertical top portions 38b and rearwardly inclined bottom portions 380. The inclined bottom portions 380 of the slots 380/. are in the extended portions of the plates 38 and these extended portions of the plate afford inclined top edges 3811 in the path of the switch I! as will be more fully hereinafter described.

The cam assembly l3, as shown in Figure l, is secured at its bottom to the piston rod la of the cylinder l5 to be raised and lowered while guided by the rollers 36 of the carrier M. The rollers 22 of the split die carrier 18 ride in the slots 33b of the plates 33 and, as will be evident from Figure 1, as the assembly [3 is raised by the piston rod l5a, the rollers 22 will shift the carrier l8 forwardly when the rollers ride from the slot portion 33d along the offset portion 330 to the forward end of this offset portion. During this cycle of movement, the split upsetting punch 23 is shifted from the position shown in Figure 1 to the position shown in Figure 4, whereupon the projecting portion T1 of the tube T is bowed or buckled to form a flared leg T2 pressed against the die face I lb and an inturned flange leg T3 extending inwardly from the flared portion T2 and formed by the concave face 23 of the split punch 23. Prior to the engagement of the punch 23 with the end of the tube T, the leading end of the tube has been placed around the mandrel 29 and the dies l I have been closed by the cylinders Hi to grip the tube T in their recesses Ha while the mandrel prevents collapse of the gripped tube. In this position, as shown in Figure l, the rollers 32 on the mandrel 29 are in the portion 38b of the slots 38a in the plates 33. It will be noted that the rollers 32 are longitudinally a igned with the rollers 22, and that the portion 38b of the slot 38 extends along a straight vertical path during the time that the rollers 22 are being moved forwardly by the offset portion 330 of the slot 33b. This arrangement thus insures insertion of the mandrel into the tube before the split punch 23 is shifted forwardly to engage the tube end.

As the cam assembly 53 rises to shift the peak of the offset groove portion 330 above the rollers 22, the rollers are retracted rearwardly to withdraw the split punch 23 to a position away from the buckled end of the tube T. In this position, the split punch face 23/ will not interfere with subsequent shaping of the tube end.

As shown in Figure l, as the split punch is being retracted away from the bowed end of the tube, the rollers 28 of the cone punch or finish punch 26, which project into the slots 31a of the plates 31, are being advanced along the forwardly inclined portions 31d of the slots. This causes a forward shifting of the core punch 26 in the carrier I 8 and split punch 23 to first cause the tapered front face 26b of the punch to ride on the shoulder 23d in the split punch 23 thereby spreading the punch sections apart as shown in Figure 5 to open up the punch passage 23a for receiving the cone punch 26 therethrough. The conical end wall 2% of the cone punch 26 thereupon engages the flange T3 of the buckled tube end to form therefrom the underlapped wall T4 underlying the flared wall T2. When the cam rollers 28 are advanced forwardly to the portion 310 of the grooves 31a, the tube portion T4 6 is firmly pressed against the tube portion T1, and this portion T2, in turn, is pressed firmly against the shaping faces lib of the dies I I.

Upon completion of the forward stroke of the cone punch 26, the rollers 32 on the mandrel 29 which project into the slots 38a of the inner plates 38 begin to enter the rearwardly inclined portion 380 of these slots and the inclined top edge 38d of one plate 38 engages an actuating lever 40 of the switch I! to raise this lever and close the switch. Closing of the switch I! momentarily energizes a solenoid 4i diagrammatically illustrated in Figure 10 for releasing a lock 42 thereby permitting a spring 43 to pull a lever 44 of a valve 45 for shifting the valve to the position shown which connects the fluid inlet 46 with intake hoses 41 on the ends of the cylinders l6 which are adjacent the dies II and, at the same time, connects hoses 48 on the other ends of the cylinders with the outlet 49. Fluid under pressure is thereby admitted to the cylinders on one side of the pistons and is exhausted from the cylinders on the other side of the piston to effect an opening of the dies to the position shown in Figure 3.

After the dies II are opened, the inclined portion 380 of the groove 38a retracts the rollers 32 to move the mandrel 29 out of the tube. During this retracting movement, however, the cone punch 26 remains in engagement with the tube portion T4 as shown in Figure 6, so that retraction of the mandrel cannot deform the shaped tube end or pull the tube through the dies.

From the above descriptions it should therefore be understood that the leading end of a tube T is placed over the mandrel and seated in the open dies H with the cam assembly i3 at the bottom of its stroke, as shown in Figure 1. When the tube end is properly seated, the valve handle 44 is shifted to engage the lock 42 whereupon fluid will enter the outer ends of the cylinders I6 and will be removed from the inner ends of the cylinders to shift the pistons for closing the dies to grip the tube in the dies and around the mandrel. The cam assembly [3 is then raised to advance the split punch 23 against the projecting end of the tube to deform the portion T1 to the bowed shape of Figure 4. Upon completion of this step, the split punch is retracted away from the bowed end of the tube and the cone punch 26 is advanced to open the split punch and engage the flange T3 of the bowed tube end for lapping it under the flared portion T2 as shown at T4 in Figure 5. Continued upward movement of the cam assembly then actuates the switch I! for momentarily energizing the solenoid 4| and permitting spring 43 to shift the valve 45 to open the dies shown in Figure 3. The mandrel 29 is then retracted from the tube while the cone punch is held against the tube wall T4 shown in Figure 6. The tube with the double lapped flared end is then removed from the dies and the cam assembly I3 is lowered, to return it to its starting position.

If desired, instead of pressing the active end face 262; of the cone punch 26 on the shoulder 23d of the split. punch 23, to open this split punch (see Fig. 9), the cone punch can be equipped with dowel pins 50 having rounded outer ends 50a for riding on a secondary shoulder 239 in the split punch 23 rearwardly from the shoulder 2311. These pins 50 will engage the shoulder 239 before the active face 26b of the cone punch reaches the shoulder 23d, whereupon thesplit a'e 'sopis 7 punch w'ill'be opened without subjecting the active face 26b to any rubbing action.

The machines of this invention, as will be apparent from the above descriptions, provide full support for the tube portion being acted on and successively buckle and underlap the tube ends. Uniformity of the buckling and underlapping op- 'erations is insured by the centering of the upsetting and underlapping punch on the mandrel which supports the gripped tube. Misalignments are thereby eliminated.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the -scope of the appended claims.

I claim as my invention:

:1. A machine for forming double lapped flared ends on "tubes which comprises coacting dieshaving 'tube gripping recesses and tapered flareshaping faces, a punch assemblyineluding -telescoped mandrel, cone punch, and split bending punch parts, a carrier for said assembly, a bear ing slidably supporting said carrier, means for shifting said carrier to advance and retract the bending punch toward and away from a tube in said dies, means for retracting said mandrel out of a tube in said dies, means for advancing and retracting said cone punch on said mandrel and in said bending punch, said co'ne punch having-an inclined cam face coasting with tapered houb ders inwardly --disposed on said split bending punch for spreading the sections thereof the cone punch is advanced into operative position, and means for automatically opening said dies upon completion of the cone punch operation to permit retraction of said mandrel.

2. A double lap flaring machine comprising coasting dies having tube-gripping recesses and flare-shaping faces, means for opening and closing said dies, a mandrel adapted to receive a tube thereon, said dies adapted to receive the tube on the mandrel, a split bending punch slidable on said mandrel and having an active face for buckling the end of a tube to form a flare bottomed on the shaping face of the dies and an inturned flange bottomed on the mandrel, a finish punch slidable on said mandrel in said bending punch and having an active end face for underlapping the inturned flange on said tube against the flared wall of the tube to form a double lapped flared wall, said end face of said finish punch coacting with tapered inner shoulders formed on said split bending punch for spreading the sections of the split bending punch, and a control assembly for successively closing the dies around the mandrel-supported portion of the tube, advancing the upset punch against the tube end, retracting the upset punch, advancing the finish punch against the tube end, opening the dies, and retracting the mandrel from the tube.

3. A machine for forming double-walled flared ends on tubes which comprises coacting dies having tube-seating and flare-shaping surfaces, a compound punch assembly coac ting with said dies including telescoped relatively movable split bending punch, finish punch, and mandrel parts, said finish punch being slidable through thespllt bending punch, said mandrel part being slidable through the finish .punch and the split bending punch parts, means disposedon the finish punch coacting with means internally :formed on the split bending punchfor spreading the sections thereof, and cam means for successively inserting the mandrel in a tube, closing the 'diesthereabout, advancing the bending punch 'againstthe tube, retracting the bending punchy-advancing the finish punch against the tube, opening the dies, and retracting the mandrel'and the finish punch from the tube.

4. A machine for forming flared ends ontu'bes which comprises a set of shaping dies, a compound punch coacting with said dies, said punch including a shiftable carrier, a-plurality'of bending punch segments shifted on said carrier and together defining an active end face for "bending the end of a tube projecting from said diesfito form a flared portion of thetube against the shaping face of the dies and to'formaninturned end flange on the divergent end of the flared tube portion, a finish punch slidable throughsa'id bending punch to lap said end flange portion of the tube against'the flared tube portion, said finish punch having means thereon coacting with inwardly formed tapered means on said bending punch segments to radially spread apart said ents, and a mandrel slidable through said iinisn ,punch, to project therefrom for supporting the tube enol collapse and for guiding the inturned end flangeunder the flared tube portion.

5. A machine for forming double-lapped flared ends on tubes which comprises coacting dies having tube-gripplngfaces and flare-defining faces, a compound punch assembly coacting with said dies, said assembly including a mandrelfor receiving a tube to align the tube for seating in said dies, the peripheral face vof said mandrel supporting the tube againstinward collapse and limiting the inward deformation of the tube end, a finish punch slidable on said mandrel and having an active end face for coacting with the end of the tube, a longitudinally split bending punch slidable on said finish punch, said split punch having a concave active end face converging tcward the mandrel, a carrier for the sectionsof the split punclnmeans pivotally connecting said sections with said carrier, said pivot means being positioned radially outward fromthe active portions of the end face of the split bending punch, the concavity of said active portions maintaining the split punch .in closed position as'it is loaded against the tube end to form -a bowed tube end portion with one .-leg bottomed against the shaping face of the die and a second leg extending inwardly from the bowed portion to the peripheral face of the mandrel, coacting means on said finish punch andsaid bending punch sections forspreading the bending punch as the finish punch is advanced therethrough to act on the inwardly extending leg .on the bowed portion of the tube for underlapping said leg against the outwardly flared portion of the tube, and cam mechanism for successively advancing the bending punch against the tube end-to buckle the tube end against the dies, retracting the bending punch away from the buckled end of the tube, advancing the finish punch against the buckled tube end, and retracting the mandrel while maintaining the finish punch against the finished end of the tube.

6. A double lap tube flaring machine which comprises coacting dies defining a tube-gripping recess and a tapered shaping face, cylinders for opening and closing said dies, a compound punch coacting with said dies including a mandrel adapted to receive a tubeithereon and align the tube for seating in said dies, a split bending punch having tapered shoulders slidable on the mandrel for bending the ends of the tube against the shaping face of the dies, and a cone punch for forming a double lap on the bent end of the tube, said cone punch having an inclined face complemental to the tapered shoulders of said split bending punch, a cam assembly for actuating the parts of the compound punch, a carrier for said cam assembly, a cylinder for actuating said cam assembly, and means controlled by said cam assembly for actuating the cylinders of said dies, said cam assembly being constructed and arranged to extend the mandrel beyond the punch for receiving the tube to align the tube in the dies to close the dies upon the mandrel-supported tube, to next advance the bending punch on the mandrel against the tube end, to retract the bending punch away from the tube end to advance the finish punch on the mandrel against the tube, to open the dies, and to retract the mandrel out of the tube.

EDWIN A. on VOSS.

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